A clock signal is a type of signal that may regularly oscillate between a logical high state and a logical low state. A clock signal, particularly the transitions between high and low states, may be used in synchronous digital circuits, such as an integrated circuit (IC), to coordinate the movement of data between synchronous data storage elements.
An IC clock may be generated on the IC, or may be generated by an external clock generator connected to the IC. A clock signal may have a specified, fixed frequency, and the timing of logic circuits may be designed to operate in accordance with this fixed frequency. A clock signal may be coupled to a number of synchronous storage elements through a clock distribution network that may include a clock distribution structure such as a clock grid, or clock tree. The distribution network may also include active circuits, such as buffers, to provide appropriate drive levels for a particular distribution structure.